The known collection optic assembly illustrated in FIGS. 1 and 2, consists of a barrel spherical collection lens 9 and seven bundles of fiber optic strands 11, each bundle 11 dedicated to a specific photon sensing detector (not shown). Each fiber bundle 11 contains over 1000 fiber optic strands. One fiber optic bundle 13 is located in the center of the six surrounding bundles 15. All seven fiber optic bundles 11 are pre-cast and end polished to precision diameters prior to assembly. This center bundle 13 is aligned to the system boresight axis. In the such a configuration, these six surrounding bundles are spaced at 60° with respect to each other and inclined at 14° with respect to the center bundle. They are also sized and positions to be in tangential contact to the center bundle and to each other. These bundles are epoxied into a ferrule (not shown) having precision sized gap and precision angled holes. Precision ferrules, fixtures and skilled technicians are required to properly fabricate and assemble the collection optic assembly. As illustrated in FIG. 2, significant space is left in the ferrule between the bundles 13,15 to allow for the correct orientation with respect to the barrel lens 9. In this previous configuration, it was necessary to maintain a precision air gap 17 between the polished ends of the seven fiber bundle to the rear surface of the collection lens within +/−0.001 inches or less.
The previous design yielded poor gain curve performance in the center of the field of view (FOV), thereby resulting in poor angle resolution. This was a key system performance parameter of seekers since most weapon systems typically track in the center of the FOV at the termination range.
Expensive component costs and fixture costs. Difficult assembly requiring skilled technicians. High number of assembly process steps.
What is needed, therefore, are techniques to optimize the seeker gain curves to generate a uniform angle performance over the 14 degree linear field of view (FOV).